Artificial respiration apparatus



March 10, 1959 T. C..HUXLEY m ARTIFICIAL RESPIRATION APPARATUS 2Sheets-Sheet 1 Filed Oct. 30, 1953 INVENTOR. 3 Thomas C. Huxley IIIATTORNEYS mm m em n ARTIFICIAL RESPIRATION APPARATUS Thomas 'C. HuxleyIII, Manhasset, N. Y., assignor t Conitech, Ltd., New York, N. Y., acorporation of New York Continuation of application Serial No. 341,037,March 3, $953. This application October 30, 1953, Serial No.

'24 Claims. (Cl. 137-63) This invention relates generally toimprovements in nited States Patent C) artificial respiration apparatusand, more particularly, to 1 improvements in devices for supplying airto a patient for breathing purposes through the patients mouth.

Une object of the present invention is the provision of an improvedpositive pressure device, adapted for use with a cyclically operable airpump adapted to alternately produce sub-atmospheric pressure andsuper-atmospheric pressure, which is eflective to cyclically supply airdirectly to a patient for breathing purposes.

Another object of the present invention is the provision of an improvedpositive pressure device of the afore-noted character which is adaptedto be used in association with the air pump to supply air directly to apatient when the cuirass is removed especially in cases where herequires treatment necessitating removal of the cuirass.

Another object of the present invention is the provision in artificialrespiration apparatus having a pump and control unit adapted foroperative association with a positive pressure device of the aforenotedcharacter, of pressure indicating means positioned in close proximity tothe control unit with said indicating means measuring pressure directlysupplied by said device.

Another object of the present invention is the provision in artificialrespiration apparatus of the above character of interchangeable couplingmeans for interconnecting the pump and control unit to the positivepressure device whereby the proximity of the positive pressure device tothe pump and control unit may be varied.

Yet another object of the present invention is the provision of agenerally improved positive pressure device of the aforenoted characterwhich is simple in design and construction, economical to manufacture,and highly efficient in the accomplishment of its intended purposes.

The above and other objects, features and advantages of the presentinvention will be more fully understood from the following descriptionconsidered in connection with the accompanying illustrative drawings.

In the drawings:

Fig. 1 is a perspective view of the positive pressure device formedaccording to the present invention shown connected to respirator pumpingapparatus;

Fig. 2 is a longitudinal sectional view of the positive pressure deviceshowing the position of the parts under one pressure condition;

Fig. 3 is a view similar to Fig. 2 showing the position of the partsunder another pressure condition; and

Fig. 4 is a fragmentary longitudinal sectional view of the positivepressure device showing the parts thereof under still another pressurecondition;

Fig. 5 is a view similar to Fig. 1 showing a modified form of positivepressure device positioned in close proximity to a bed;

Fig. 6 is a sectional view, on an enlarged scale, taken 2,876,785Patented Mar. 10, 1959 on the line 6-6 of Fig. 5 and showing theposition of the parts under one pressure condition;

Fig. 7 is a view similar to part of Fig. 6 showing the position of theparts under another pressure condition;

Fig, 8 is a perspective view of the positive pressure device shown inFigs. 5-7 with the device shown connected to respirator pumpingapparatus by means of a modified form of coupling device; and

Fig. 9 is a fragmentary longitudinal sectional view showing theinterconnection of the coupling device shown in Fig. 8 to the respiratorpumping apparatus.

With reference to the drawing, and more particularly with reference toFig. 1 thereof, there is shown respirator pumping apparatus 10 housingan air pump which is cyclically operable to alternately producesub-atmospheric pressure and super-atmospheric pressure at the port 12of said apparatus. The respirator pumping apparatus 10 may be of anydesired design and construction and the apparatus illustrated is of thetype fully shown and described in my copending application Ser. No.295,181, filed June 24, 1952, now Patent No. 2,762,200, for ArtificialRespiration Apparatus and assigned to the assignee of the presentapplication. The port 12 of apparatus 10 is normally adapted to be influid communication with one or more cuirasses and said apparatus willbe effective to periodically supply air to and withdraw air from saidone or more cuirasses. The cuirass may be of the type shown in my PatentNo. 2,466,108 or in my pending application, Ser. No. 294,163 filed June18, 1952, now Patent No. 2,772,673, both assigned to. the assignee ofthis application. It will be understood that the air pump disposed inapparatus 10, when operatively associated with a cuirass, alternatesbetween partial vacuum and normal pressure of the air within saidcuirass at a controlled and variable rate to successfully simulatenormal respiration. At times it is necessary or desirable to supply airdirectly to a patient when the cuirass is removed from the patient sothat such patient may be treated at body areas which are normallycovered by the cuirass. At such times when the cuirass is removed fromthe patient, the positive pressure device 14 may be associated withapparatus 10 in a manner to be subsequently described in detail so as tosupply the air directly to the patient.

The positive pressure device 14 is adapted to be interposed between theconduit 16 and the port 12 in fluidfiow relation with the latter, itbeing noted that the conduit 16 terminates in a mouth piece 18 which isadapted to be inserted in the patients mouth for supplying air directlyto the patient. Thus in the normal use ofv the apparatus a cuirass willbe operatively associated with the apparatus 10 and when said cuirass isremoved from the patients body it is merely necessary to connect thepositive pressure device 14 to the port 12 whereby it will be apparentthat said device is adapted to be alternately used in association withthe apparatus 10. As fully shown and described in the aforereferred tocopendingapplication, it is to be noted that the port 12 is normallyadapted for association with a complementary conduit which is in fluidcommunication with a cuirass and for operatively associating thepositive pressure device 14 with the apparatus 10 it is merely necessaryto remove said conduit connected to the cuirass and secure said positivepressure device to port 12. The conduit 16 is adapted for periodic fluidcommunication with the port 12 whereby to periodically supply air atsuper-atmospheric pressure to the patient.

The positive pressure device 14 comprises a casing 20 housing valvemeans for interconnecting port 12 and posed in apparatus 10 is operativeto produce super-atmospheric pressure at said port, said valve meansbeing also operative to disconnect the port 12 from fluid communicationwith the conduit 16 when the pump is operative to producesub-atmospheric pressure at said port.

' More particularly, the valve means for periodically interconnectingthe port 12 and conduit 16 for fluid communication comprises a shuttlevalve 22 which is operativeiy associated with the passages 24 and 26,said shuttle valve being adapted to move from the position shown in Fig.3 to the position shown in Fig. 2 when super-atmospheric pressure isadmitted to the tubular portion 28 of casing 20. It is to be noted thatthe tubular portion 28 defines a port 30 at one end of the device 14 andthat said portion is adapted to be received in port 12 of the apparatus10, said device when operatively associated with the apparatus being inan upright position. The shuttle valve 22 is of disk-like formation andhas a central aperture 32 extending therethrough. The passage 24 is ofannular configuration and is defined in the plate 34 of the casing 20,said passage communicating with the interior chamber 36 of said casing.The annular passage 24 is in fluid communication at all times with theport 30 and said passage is adapted for fluid communication with theport 38 defined by the tubular portion 40 when the shuttle valve 22 isin the raised position, shown in Fig. 2. The passage 26 which is influid communication with the atmosphere through the circumferentiallyspaced series of apertures 27 is out of communication with the passage24 when the shuttle valve 22 is in the raised position shown in Fig, 2.The inner end 42 of the tubular portion 40 constitutes a valve seat forthe shuttle valve 22 when the latter is in the raised position, it beingnoted that the port 38 is in fluid communication with the passage 26when the shuttle valve 22 is in its lowered position. The plate 34 whichhas the annular passage 24 defined therein is provided with an annularrim 44 which is adapted to provide a valve seat for the shuttle valve 22when the latter is in its lowered position, as shown in Fig. 3:. Thevalve 22 is gravitationally urged in its lowered position in which thepassage 24 will be closed and said shuttle valve is guided for verticalmovement in casing by the annular interior surface portion 46 of saidcasing. When air at super-atmospheric pressure flows into port from port12 the shuttle valve 22 will be pressure urged into the position shownin Fig. 2 in which said air at super-atmospheric pressure will enter theannular passage 24 and discharge through port 38, said air entering theport 38 through the central passage 32 in the shuttle valve. Thus whenair at super-atmospheric pressure is admitted into the interior chamber36 of the casing 29, the shuttle valve 22 responds substantially withoutdelay in a single step operation to close the passage 26 leading to theatmosphere and open the passage 24 permitting the latter to be in fluidcommunication with passage 32 and port 38, the latter in turn being influid communication with the mouthpiece 18 through conduit 16. it is tobe noted that the end 16' of the conduit 16 is dimensioned complementaryto the end portion 48 of tubular portion 40 and is adapted to bepositioned thereon in fluid-tight relation therewith. From the above itwill be apparent that the mouthpiece 18 and port 12 will be in fluidcommunication with each other when the pump of apparatus 10 is operativeto produce super-atmospheric pressure at said port. Thus whensuper-atmospheric pressure is admitted into the chamber 36 of casing 20the shuttle valve 22 will be pressure raised to close the passage 26 andwill be at the same time open passage 24 for fluid communication withport 38 through the shuttle valve passage 32. It will also be apparentfrom the above that when sub-atmospheric pressure is applied to theinterior chamber 36 of the casing 20, the shuttle valve 22 will seat onannular rim 44 whereby to shut off the passage 24 from fluidcommunication with the passage 32 and consequently with port 38. It isalso to be noted that when the shuttle valve is in its lowered positionand seated on rim 44 the port 38 will be in fluid communication Wtih thepassage 26 and will accordingly be in fluid communication with theatmosphere. Thus when sub-atmospheric pressure is applied to the chamber36 of the casing 20 the patient can breathe out through the passage 26leading to the atmosphere. It is to be noted that the elastic recoil ofthe patients lungs will allow the patient to exhaust air after receivingair at superatmospheric pressure in the above manner. Thus whenapparatus 10 is operative to produce sub-atmospheric pressure in thechamber 36 of casing 20 the patient can readily breathe out through theport 33 which under such conditions will be in fluid communication withthe passage 26, and apertures or vents 27.

The casing 20 is also provided with separate valve means for venting theinterior chamber 36 of said casing to the atmosphere when apparatus 10is operative to produce sub-atmospheric pressure at port 12 andconsequently in said interior chamber 36 of said casing, said separatevalve means comprising an annular valve member 50 which is operativelyassociated with a companion annular port 52 which communicates with theatmosphere. The valve member 50 is adapted to provide fluidcommunication between the chamber 36 and the atmosphere when apparatus10 is operative to produce sub-atmospheric pressure at port 12. Thus thevalve member 50 is normally gravitationally urged in a position to closethe port 52 and when sub-atmospheric pressure is applied to the chamber36 the valve member 50 will be vertically moved to the raised positionshown in Fig. 3 in which said valve member will abut the peripherallyextending shoulder 54 disposed in the casing 20. Thus the valve meansconstituted by the valve member 50 and its associated port 52 is adaptedto vent the chamber 36 to the atmosphere when sub-atmospheric pressureis applied to said chamber. The valve member 50 which is of flatdisklike formation is centrally apertured and is guided for verticalmovement by the complementary annular portion 56. of the casingstructure 20. It will also be apparent that when super-atmosphericpressure is applied to the chamber 36, the port 52 will be pressureclosed by the valve member 50, and when sub-atmospheric pressure isapplied to said chamber said valve member will be raised against theannular shoulder 54 to vent said chamber to the atmosphere through theannular port 52.

The casing structure 20 is further provided with independent valve meansfor limiting the amount of superatmospheric pressure supplied to theconduit 16 from the port 12. More particularly, the tubular portion 40at its lower end is provided with a series of apertures 58 spacedcircumferentially of said portion, said apertures communicating with theannular chamber 60 defined in the casing 20. Tubular portion 40,interior of the casing portion 62 of casing 20, has operativelyassociated therewith the valve member 64, the latter beinggravitationally urged to the position shown in Figs. 2 and 3, and beingmovable to the position shown in Fig. 4 when the amount ofsuper-atmospheric pressure entering chamber 36 is above a predeterminedamount' The annular valve member 64 has a lower part 66 of a preferablyresilient material of annular configuration which is adapted to seat onthe valve seat portions 68 disposed in the casing portion 62 when saidvalve member is in its normal lowered position shown in Figs. 2 and 3.When the pressure admitted to the chamber 36 is above a predeterminedmaximum amount the valve member 64 will be raised from the seat 68 andthe excess pressure will be vented to the atmosphere through the annularpassage 70 and the series of circumferentially spaced apertures '72 inthe casing portion 62 as shown in Fig. 4. It will be apparent that whenthe valve member 64 is seated on seat 68 the annular passage 70 and theapertures 72 will be out of fluid communication with the chamber 60whereby air supplied to the chamber 36 will be discharged through themouthpiece 18 and into the patients mouth. Thus the valve member 64 andassociated structure constitutes means for limiting the amount ofsuper-atmospheric pressure supplied to a patient through the conduit 16to a predetermined maximum.

If desired, annular chamber 60 may be provided with an outlet port 74which is in fluid communication with the conduit 76, the latter beingoperatively associated with any suitable pressure gauge (not shown).Thus the port 74 is provided to tap the pressure from the chamber 60 toa suitable pressure gauge so that pressure conditions in the casing 20may be noted at a glance. A suitable filter 78 may be disposed in thechamber 36 for filtering the air supplied to the patient by theapparatus 10, said filter being of conventional construction and beingsecured in the casing 20 in any conventional manner. In the illustratedembodiment the casing portion 80 of casing 20 is provided with anannular groove 82 which is adapted for the reception of the annularfilter 78, the latter being dimensioned complementary to said annulargroove. Any suitable means may be provided for the disassembly of thecasing 20 and in the illustrated embodiment the casing portion 80 isformed of two parts 80' and 80 which are provided with peripherallyextending flanges 84 and 86, respectively, which are adapted to mate inthe assembled condition of the device 14. The flanges 84 and 86 will beprovided with a plurality of circumferentially spaced apertures 88 whichare adapted to register for the reception of fastener elements 90, thelatter providing a ready means for the assembly and disassembly of thecasing portion 80. Although only one fastener element 90 is shownassociated with the registered apertures 88 of the flanges 84 and 86, itis to be understood that a plurality of said fastener elements areutilized and will be spaced circumferentially of the flanges 84 and 86,corresponding to the spacing of the registered aperatures 88.

From the above it will be apparent that the positive pressure device 14aforedescribed is adapted to be used alternately in association with acuirass to supply air directly to a patient when the cuirass is removedfrom the patient so that he may be treated at body areas which arenormally covered by the cuirass. When the cuirass is re-positioned onthe patients body the positive pressure device 14 may be removed fromunit 10 and the latter will be operatively associated with said cuirassto simulate the breathing operation. Thus sub-atmospheric pressure andsuper-atmospheric pressure will be alternately and cyclically producedin the chamber 36 of the device 14 and only the super-atmosphericpressure will flow to the mouthpiece 18 and consequently to the patientsince the application of sub-atmospheric pressure to the chamber 36 willbe efiective to close the passage 24, at which time the mouthpiece willbe in fluid communication with the passage 26 leading to the atmosphere,said passage providing means for permitting the patient to exhaust airafter the application of positive pressure.

It will be understood that the valve member 64 is of a preselectedweight so as to raise from seat 68 when the amount of super-atmosphericpressure entering chamber 36 exceeds a predetermined amount. The maximumamount of pressure entering chamber 36 may be varied by substitutinganother valve member 64 of proper weight in the assembly or, if desired,adjustable spring means may be associated with valve member 64 wherebyto provide a readily adjustable means for limiting the maximum amount ofpressure supplied to the patient.

With reference to Figs. -8, there is shown a positive pressure device100 which is similar to the positive pressure device 14 aforedescribedin detail except in the respects now to be specifically noted. Thepositive pressure device 100 is adapted to be interposed between theconduit 16 and the port 12 of apparatus in fluid flow relation with saidport, it being noted that the conduit 16' terminates in a mouth piece18' which is adapted to be inserted in the patients mouth for supplyingair directly to the patient in the aforedescribe'd manner. The positivepressure device comprises a casing 20' which houses valve means forinterconnecting port 12 and conduit 16' for fluid communication when thepump disposed in apparatus 10 is operative to produce super-atmosphericpressure at said port, said valve means being also operative todisconnect the port 12 from fluid communication with the conduit 16 whenthe pump is operative to produce sub-atmospheric pressure at said port.The casing 20' is provided with a casing part 102 which defines theauxiliary chamber 104, the latter being vented to the atmosphere bymeans of the vent holes 106. Disposed between the interior chamber 36'and the auxiliary chamber 104 is an annular passage 108 which isnormally closed by the annular valve member 110. Disposed in theauxiliary chamber 104 is a conical spring 112 of the compression typewhich is adapted to bias the valve member 10 into the closed position asshown in Figs. 6 and 7. Thus one end of the compression spring 112coacts with an adjacent face of the valve member 110 and the oppositeend of said spring coacts with the interior face 114 of the casing part102. Thus the chambers 36' and 104 are normally out of fluidcommunication and under excess super-atmospheric pressure conditions thevalve member 110 will be displaced from its seat 111 whereby excesssuper-atmospheric pressure will be vented to the auxiliary chamber 104and then to the atmosphere through the vent ports 106. Accordingly theannular valve member 110 is operative to vent super-atmospheric pressureabove a predetermined amount supplied through the port 12 to theauxiliary chamber 104 which is vented to the atmosphere. The maximumamount of pressure permitted in chamber 36 may be varied by substitutinganother spring 112 of the desired tension or, if desired, adjustablespring means may be associated with the valve member 110 whereby toprovide a ready means for limiting the maximum amount of pressuresupplied to the patient. As aforedescribed, the valve means forperiodically interconnecting the port 12 and conduit 16 for fluidcommunication comprises a shuttle valve 22' which is operativelyassociated with the passages 24' and 26', said shuttle valve beingadapted to move from the position shown in Fig. 7 to the position shownin Fig. 6 when super-atmospheric pressure is admitted to the tubularportion or fitting 28' of casing 20'. The passage 26 is in fluidcommunication with the auxiliary chamber 104 through thecircumferentially spaced series of apertures 27' whereby it will beapparent that when the shuttle valve 22' is in the raised position thepassage 26 and chamber 104 will be out of fluid communication with thepassage 24'. Thus when air at super-atmospheric pressure is admittedinto the interior chamber 36' of casing 20, the shuttle valve 22 willclose the passage 26' leading to the atmosphere through chamber 104 andopen the passage 24' permitting the latter to be in fluid communicationwith the mouthpiece 18' through conduit 16'. It is also to be noted thatwhen the shuttle valve 22' is in its lowered position the port 38 willbe in fluid communication with the passage 26' and will accordingly bein fiuid communication with the atmosphere through the auxiliary chamber104 which, as aforenoted, is vented to the atmosphere. Thus whensub-atmospheric pressure is applied to the chamber 36' the patient canbreathe out through the passage 26 leading to the chamber 104 which isvented to the atmosphere. From the above it will be apparent that theauxiliary chamber 104 is in fluid communication at all times withpassage 26 and is adapted length of tubing in fluid sealing relationtherewith.

The opposite end 122 of the length of tubing 120 is connected to fitting124 in fluid sealing relation therewith, it being noted that saidfitting is also interconnected with the tapered tube 126. The smallerdiameter end 128 of the tube 126 is interconnected with the mouthpiece18 in fluid sealing relation therewith. From the above it will beapparent that the conduit 16- for interconnecting device ltltl to themouthpiece is constituted bysthe length of tubing 12d, fitting 124 andtube 126. The-device 100 is preferably provided with a suitable hook 130which is adapted for a purpose which will be evident from thedescription which follows, the threaded shaft part 132 of said hookbeing adapted to be received in aligned apertures provided in the part134 and the wall part 136 of casing part 162. -It will be understoodthat the aperture provided in part 134 is threaded complementary to part132 and that the latter together with screws 133 provide for thesecurement of part 134 to casing part 1G2. Threadedly engaged on shaft132 is a nut 138 which is adapted to be clamped against part 136 forclamping hook 130 in its adjusted position and for securing part 134topart 132 as will be readily apparent. Where necessary or desirable thehook 130 may be utilized to support the device 1% at a convenientposition, for example on the support S of bed B. Accordingly the hook130 may be utilized to support the device 100 at a position dictated byconvenience or necessity and it will be readily apparent that said hookmay be interengaged with any suitable support means for supporting thepositive pressure device at the desired position.

Pursuant to the present invention there is provided an arrangement inwhich the pressure indicating means is positioned in close proximity tothe controls of apparatus with said indicating means measuring pressureat port 38' and consequently the pressure being supplied to themouthpiece 13 and to the patient. Certain features of this arrangementare fully shown and described in the copending application of Nelson G.Kling and Thomas C. Huxley III for improvements In ArtificialRespiration Apparatus, Serial No. 383,792, filed October 2, 1953, newPatent No. 2,832,335 and the copending application of Nelson G. Klingand Thomas C. Huxley III for Improvements in Artificial RespirationApparatus, Serial No. 362,316, filed June 1?, 1953, now Patent No.2,779,329, said applications being assigned to the assignee of thepresent invention. As fully shown and described in said copendingapplications, the pump housed in apparatus 10 comprises a fixed head 150and a piston or relatively movable head 152 which is mounted forreciprocation, said fixed head and said movable head definingtherebetween the sealed pumping chamber 154. The instrument pane 156 ofapparatus lU-has suitably mounted thereon a pressure gage (not shown)which is in close proximity to the control knobs of said apparatus. Thepressure gage disposed on instrument panel 156 is adapted to measurepressure directly at port 38 and consequently the pressure sup plied toa patient in a manner now to be described in detail. The pressure gageis provided with a pressure transmitting tube portioniSfi which extendsin pumping chamber 154 and terminates in a free end portion 169 which isconstituted by a fitting which is adapted for a purpose which will beevident from the description which follows. It is to be here noted thatapparatus it) corresponds in allrespects to the corresponding apparatusof the aforereferred to eopending applications. Thus the fitting 166 isconstituted by a tapered end portion of the tube portion 158 and isprovided with a peripln erally extending groove having a sealing ring162 positioned therein. The tube portion 158 is in iiuid flow re lationwith the pressure indicating gage on the instrument panel 156 andterminates in a free end portion constituted by the fitting 168 which isdisposed in the region of fitting 164 which defines port 12. The tubeportion 158 is supported centrally of fitting 164 in a fixedrelativeposition by the radially extending arms 166; which, are received in theperipherally extending recess 168, as aforedescribed in detail in theaforereferred to copending applications.

Disposed in casing 20 in coaxial relation therewith is a longitudinallyextending open ended pressure communication tube 170 which is adapted tobe interconnected with the tube portion 158 and consequently to thepressure indicating gage in a manner to be described in detailhereinafter. The thickened central portion 172 of plate 34' is aperturedtherethrough as indicated at 174 for the reception of tube 170, saidportion 172 being adapted to support tube 179 in casing 26 inconjunction with the radially extending arms 176 which are secured tosaid tube and in recess 177 as aforedescribed with reference to arms166. Thus the tube 179 is supported centrally of casing 2i) atlongitudinally spaced points by means of the portion 1.72 and by theradially extending arms 176. The free end portion 173 of tube 279terminates in the region of port 38' whereby the pressure indicatinggage is adapted to indicate pressure at said port and consequently thepressure supplied to the patient through mouthpiece 18' when device 1%is operatively associated with apparatus 10 in the manner to bedescribed hereinafter. The free end portion 18% of tube 179 is disposedin the tubular portion 28 in coaxial relation therewith and isconstituted by a tapered fitting which corresponds in all respects tothe fitting aforedescribed. Thus the pressure communication tube isadapted to be interconnected with the tube portion 158 in a manner to bedescribed hereinafter and when so connected the pressure indicating gageof apparatus 10 is adapted to directly indicate pressure supplied to apatient during the positive pressure phase of the pumping means of saidapparatus.

The instant artificial respiration apparatus is provided withinterchangeable coupling 'or conduit means for interconnecting the pumpand control unit of apparatus 10 to the positive pressure device 169whereby the proximity of the latter device to the pump and control unitmay be varied. Thus the positive pressure device 100 may beinterconnected with apparatus 10 by means of the coupling member 182shown in Fig. 6 or the flexible tube 184 which is similar in allrespects to the corre sponding tube of the aforereferred to copendingapplications.

The coupling member 182 comprises a rigid body part 186 which terminatesin structurally similar integral fittings 183 and 1%, said fittingsbeing formed complementary to the tubular portion or fitting 23' andfitting 164 of device 1 59 and apparatus iii, respectively. It will beunderstood that fittings 188 and 19d and fittings 28' and 164 arestructurally similar and companion pairs of said fittings are adapted tobe releasably interconnected in fluid sealing relation whereby couplingmember 132 when interconnected with apparatus 1i? and device 100 definesa fluid passage between ports 12 and 39. The fittings 28' and 164 arepreferably provided with a sealing ring 1?.2 whereby to provide for afluid tight interconnection between coupling member ISZ, apparatus 10,and device 100. Longitudinally extending in member 182, in coaxialrelation therewith, is a pressure communication tube 1%4 which issupported in the body part 186 of member 132 by means of the radiallyextending arms 196 which are structurally similar to arms 166 and 1'76.The pressure communication tube 194 terminates in structurally similarfittings 1% which are disposed in the region of the fittings 188 and 190in fixed relation therewith. The fittings 198 are formed complementaryto the fittings 168 and 13b aforedescribed and are adapted forreleasable interconnection therewith in fluid sealing relation. Thusfittings 160 and are structurally similar and are formed complementaryto the structurally similar fittings 198. it is to be noted thatfittings 198 and 198 are disposed in a fixed relation with the fittings188 and 190, respectively, said arrangement providing for thesimultaneous plug-in connection of the body fittings 188 and 190 and thetube fittings 198 and 198, respectively, as a unit to apparatus anddevice 100. On the interconnection of the coupling member 182 to fitting164 of apparatus 10 the companion fitting 198' will be automaticallyinterconnected with its complementary fitting 160, the latter fittingbeing associated with the pressure indicating gage on the instrumentpanel 156 in the aforedescribed manner. Thus fittings 190 and 198provide for the interconnection of the tube 194 with the fitting 160 ofthe tube portion 158 on the plug-in interconnection of the member 182with apparatus 10. Similarly on the interconnection of the couplingmember 182 with device 100 the fitting 198 will be automaticallyinterconnected with its complementary fitting 180 of tube 170 wherebythere will be defined a pressure communication passage from the pressureindicating gage to the free end portion 178 of tube 170 when said member182 is interconnected between apparatus 10 and device 100. Thus tubeportion 158 will be automatically connected to tube 170 in fluid flowrelation therewith on the interconnection of device 109 and apparatus 10with the coupling member 182. It is to be noted that either end ofmember 182 may be plugged in the apparatus 10 and device 100 in theaforedescribed manner. Thus where it is desired to connect device 100 toapparatus 10 in close proximity thereto the coupling member 182aforedescribed will be utilized to provide for said interconnection.

With reference to Figs. 8 and 9, if it is desired to connect the device100 to apparatus 10 and to position said device at a distance from saidapparatus the coupling device or conduit 184 will be utilized, saidcoupling device or conduit being structurally similar to thecorresponding conduit of the aforereferred to copending applications.Thus the conduit 184 which is adapted to connect apparatus 10 to device100 in fluid flow relation therewith is preferably of flexible andresilient construction. The terminal ends 200 of conduit 184 arestructurally identical and are in the form of fittings which are adaptedfor releasable interconnection to the fittings 28 and 164 in fluidsealing relation therewith. As aforenoted, the fittings 200 of theconduit or coupling device 184 are structurally identical whereby eitherend of said conduit may be interchangeably associated with the apparatus10 and device 100 in the aforedescribed manner. Extending longitudinallyin the conduit 184 is a pressure transmitting tube 202 which issupported centrally of said conduit at longitudinally spaced points bythe radial ly extending arms 204. Both terminal end portions of tube 202are structurally similar and define fittings 206 which are adapted to bereleasably connected to the fittings 160 and 180, which are formedcomplementary thereto. Thus the conduit 184 is adapted to be utilized inconjunction with apparatus 10 and device 100 interchangeably withcoupling member 182. One end fitting 200 of conduit 184 is adapted to beinterconnected with fitting 164 and the opposite end fitting 200 of saidconduit is adapted to be interconnected with the fitting 28 of device100. The pressure transmitting tube 202 terminates at both ends infittings 206 which are formed complementary to the fitting 160 and 180as aforedescribed, said fittings 206 being adapted for releasable fluidsealing connection with fittings 160 and 180 on the interconnection offittings 200 with apparatus 10 and device 100. Thus, as shown in Fig. 9,one end fitting 200 of conduit 184 is adapted for interconnection withthe fitting 164 of apparatus 10 and on such interconnection the fittings206 and 160 will be automatically releasably interconnected whereby toprovide for the interconnection of the tube 202 with the pressureindicating gage on instrument panel 156. The opposite end fitting 200 ofconduit 184 will be similarly interconnected with the device 100 andsaid interconnection will automatically provide for the interconnectionof a fitting 206 of tube 202 with the fitting 180 of tube 170 whereby toprovide for a pressure transmission passage from the end 178 ofi tube170 to the pressure indicating gage. Accordingly if it is desired toposition device at a distance from apparatus 10 as shown in Fig. 8, aconduit 184 will be.

' utilized to provide for the interconnection between said apparatus andsaid device. Thus companion fittings 200 and 206 of conduit 184 aredisposed in fixed relation to each other and provide for thesimultaneous connection of said fittings as a unit to ditferent devices,for example apparatus 10 and device 100. The pressure indicating gage,which is positioned in close proximity to the control devices ofapparatus 10, measures pressure directly in the region of port 38 ofdevice 100 irrespective of whether coupling member 182 or conduit 184 isutilized for interconnecting the positive pressure device 100 withapparatus 10. It will be understood that the positive pressure device 14aforedescribed may be provided with a pressure communication tubesimilar to the tube whereby to provide for the direct read ing ofpressure at port 38 from a position remote therefrom. In practice, afterdevice 100 and apparatus 10 are interconnected as aforedescribed, thepressure control knobs of said apparatus will be turned to the zero orvalve opened position and after the pump of said apparatus is operatingthe positive pressure control knob will be turned to its maximum orvalve closed position and the negative pressure control knob will beslowly turned until the pressure indicating gage indicates the desiredamount of positive pressure.

The present invention is a continuation-in-part of my copendingapplication entitled Improvements In Artificial Respiration Apparatus,Serial No. 341,037, filed March 9, 1953, now abandoned, and assigned tothe assignee of the present invention.

While -I have shown and described the preferred embodiment of myinvention, it will be understood that various changes may be made in thepresent invention without departing from the underlying idea orprinciples of the invention within the scope of the appended claims.

Having thus described my invention, what I claim and desire to secure byLetters Patent is:

1. In combination with respirator pumping apparatus having pumping meansto periodically supply air to and withdraw air from a port and a conduitadapted for periodic fluid communication with said port, a positivepressure device interposed between said conduit and said port in fluidflow relation with the latter, said device comprising a casing havingvalve means for interconnecting said port and said conduit for fluidcommunication when said pumping means is operative to supply air to saidport, said valve means being operative to disconnect said port and saidconduit from fluid communication when said pumping means is operative towithdraw air from said port, and valve means disposed in said casingindependent of said first mentioned valve means for venting said casingto the atmosphere when said pumping means is operative to withdraw airthrough said port.

2. In combination with respirator pumping apparatus having pumping meansto periodically supply air to and withdraw air from a port and a conduitadapted for periodic fluid communication with said port, a positivepressure device interposed between said conduit and said port in fluidflow relation with the latter, said device comprising a casing havingvalve means for interconnecting said port and said conduit for fluidcommunication when said pumping means is operative to supply air to saidport, said valve means being operative to disconnect said port and saidconduit from fluid communication when said pumping means is operative towithdraw air from said port, and valve means disposed in said casingindependent of said first mentioned valve means for venting said casingto the atmosphere when said pumping means is op-" erative to withdrawair through said port, and inde-'* pendent valve means provided in saidcasing for limit- 11 ing the supply of air to said conduit when thelatter and said port are interconnected for fluid communication.

3. In combination with an air pump cyclically operable to alternatelyproduce sub-atmospheric pressure and super-atmospheric pressure at aport, and a conduit adapted for periodic fluid communication with saidport, a positive pressure device interposed between said conduit andsaid port in fluid flow relation with the latter, said device comprisingcasing structure provided with valve means for interconnecting said portand said conduit for fluid communication when said pump is operative toproduce super-atmospheric pressure at said port, said valve means beingoperative to disconnect said port and said conduit from fluidcommunication when said pump is operative to produce sub-atmosphericpressure at said port, said valve means comprising a shuttle valveoperatively associated with a pair of passages, one of said passagescommunicating with said port and the other of said passagescommunicating with the atmosphere, said shuttle valve being adapted toclose said other passage and open said one passage when said pump isoperative to produce super-atmospheric pressure at said port wherebysaid port and said conduit will be in fluid communication, and meansprovided in said casing for venting said casing to the atmosphere whensaid pumping means is operative to produce sub-atmospheric pressure atsaid port.

4. In combination with an air pump cyclically operable to alternatelyproduce sub-atmospheric pressure and super-atmospheric pressure a port,and a conduit adapted for periodic fluid communication with said port, apositive pressure device interposed between said conduit and said portin fluid flow relation with the latter, said device comprising casingstructure provided with valve means for interconnecting said port andsaid conduit for fluid communication when said pump is operative toproduce super-atmospheric pressure at said port, said valve means beingoperative to disconnect said port and said conduit from fluidcommunication when said pump is operative to produce sub-atmosphericpressure at said port, said valve means comprising a single shuttlevalve operatively associated with a pair of passages, one of saidpassages communicating with said port and the other of said passagescommunicating with the atmosphere, said casing having valve seats atopposite sides, respectively, of said valve, said shuttle valve beingengageable with one of said valve seats to close said other passage andbeing simultaneously disengageable from said other valve seat to opensaid one passage when said pump is operative to producesuper-atmospheric pressure at said port whereby said port and saidconduit will be in fluid communication, said shuttle valve having anopening therethrough which is closed when said valve is engaged withsaid other valve seat.

5. In combination with an air pump cyclically operable to alternatelyproduce sub-atmospheric pressure and super-atmospheric pressure at aport, and a conduit adapted for periodic fluid commuication with saidport, a positive pressure device interposed between said conduit andsaid port in fluid flow relation with the latter, said device comprisingcasing structure provided with valve means for interconnecting said portand said conduit for fluid communication when said pump is operative toproduce super-atmospheric pressure at said port, said valve means beingoperative to disconnect said port and said conduit from fluidcommunication when said pump is operative to product sub-atmosphericpressure at said port, said valve means comprising a single shuttlevalve operatively associated with a pair of passages, one of saidpassages communicating with said port and the other of said passagescommunicating with the atmosphere, said casing having valve seats atopposite sides, respectively, of said valve, saidshuttle valve beingengageable with one of said valve. seats to close said other passage andbeing simultaneously disengageable from said other valve seat to opensaid one passage when said pump is operative to producesuper-atmospheric pressure at said port whereby said port and saidconduit will be in fluid communication, and separate valve meansdisposed in said casing for venting the latter to the atmosphere whensaid pump is operative to produce sub-atmospheric pressure at said port,said separate valve means comprising a valve member operativelyassociated with a port communicating with the atmosphere, said valvemember being adapted to open said last mentioned port when said pump isoperative to product sub-atmospheric pressure at said first mentionedport, and independent valve means disposed in said casing for limitingthe amount of superatmospheric pressure supplied to said conduit fromsaid first mentioned port.

6. A positive pressure device adapted for use with a cyclically operableair pump adapted to alternately produce sub-atmospheric pressure andsuper-atmospheric pressure, said device comprising a casing having apair of spaced ports which are adapted to be in communica tion with eachother cyclically when super-atmospheric pressure is admitted into one ofsaid ports, and valve means for interconnecting said ports whensuper-atrnos-' pheric pressure is admitted into one of said ports, saidvalve means being operative to disconnect said ports from communicationwhen sub-atmospheric pressure is applied to said one port, said valvemeans comprising a shuttle valve operatively associated with a pair ofpassages, one of said passages communicating with said one port and theother of said passages communicating with the atmosphere, said shuttlevalve being adapted to close said other passage and open said onepassage when superatmospheric pressure is admitted into said one port,and valve means disposed in said casing independent of said shuttlevalve for venting said casing to the atmosphere when sub-atmosphericpressure is admitted into said one port.

7. A positive pressure device adapted for use with a cyclically operableair pump adapted to alternately produce sub-atmospheric pressure andsuper-atmospheric pressure, said device comprising a casing having apair of spaced ports which are adapted to be in communication with eachother cyclically when super-atmospheric pressure is admitted into one ofsaid ports, and valve means for interconnecting said ports whensuper-atmospheric pressure is admitted into one of said ports, saidvalve means being operative to disconnect said ports from communicationwhen sub-atmospheric pressure is applied to said one port, said valvemeans comprising a shuttle valve operatively associated with a pair ofpassages, one

of said passages communicating with said one port and.

the other of said passage communicating with the atmosphere, saidshuttle valve being adapted to close said other passage and open saidone passage when superatmospheric pressure is admitted into said oneport, and

valve means disposed in said casing independent of said shuttle valvefor venting said casing to the atmosphere when sub-atmospheric pressureis admitted into said,

one port, said last mentioned valve means comprising a valve memberoperatively associated with a port communicating with the atmosphere,said valve member bcing gravitationally urged in a position to close itsassociated port and being adapted to open the latter whensub-atmospheric pressure is admitted into said one port' 8. A positivepressure device adapted for use with a cyclically operable air pumpadapted to alternately produce sub-atmospheric pressure andsuper-atmospheric pressure, said device comprising a casing having apair of spaced ports which are adapted to be in communication with eachother cyclically when super-atmospheric pressure is admitted into one ofsaid ports, and valve means for interconnecting said ports whensuper-atmos pheric pressure is admitted into one of said ports, saidvalve means being operative to disconnect said ports from communicationwhen sub-atmospheric pressure is applied to said one port, said valvemeans comprising a shuttle valve operatively assiciated with a pair ofpassages, one of said passages communicating with said one port and theother of said passages communicating with the atmosphere, valve seats atopposite sides of said shuttle valve, said shuttle valve being movableinto and out of engagement with said valve seats, respectively, to closesaid other passage and open said one passage when super-atmosphericpressure is admitted into said one port, and valve means disposed insaid casing independent of said shuttle valve for venting said casing tothe atmosphere when sub-atmospheric pressure is ad mitted into said oneport, said last mentioned valve means comprising a valve memberoperatively associated with a port communicating with the atmosphere,said valve member being gravitationally urged in a position to close itsassociated port and being adapted to open the latter whensub-atmospheric pressure is admitted into said one port, and additionalvalve means disposed in said casing for limiting the amount ofsuper-atmospheric pressure flowing through the other of said spacedports.

9; A positive pressure device adapted for use with a cyclically operableair pump adapted to alternately produce sub-atmospheric pressure andsuper-atmospheric pressure, said device comprising a casing having apair of spaced ports which are adapted to be in communication with eachother cyclically when super-atmospheric pressure is admitted into one ofsaid ports, and valve means for interconnecting said ports whensuper-atmospheric pressure is admitted into one of said ports, saidvalve means being operative to disconnect said ports from communicationwhen sub-atmospheric pressure is applied to said one port, said casinghaving a fitting defining a fluid passage communicating with said oneport, a pressure communication tube disposed within said fitting andextending longitudinally of the latter into said spaced parts, saidfitting having means for supporting said pressure communication tubetherein whereby to provide for the simultaneous connection of saidfitting and said pressure communication tube as a unit to differentdevices, respectively.

10. A positive pressure device adapted for use with a cyclicallyoperable air pump adapted to alternately produce sub-atmosphericpressure and super-atmospheric pressure, said device comprising a casinghaving a pair of spaced ports which are adapted to be in communicationwith each other cyclically when super-atmospheric pressure is admittedinto one of said ports, and valve means for interconnecting said portswhen super-atmospheric pressure is'admitted into one of said ports, saidvalve means being operative to disconnect said ports from communicationwhen sub-atmospheric pressure is applied to said one port, said casinghaving a fitting defining a fluid passage communicating with said oneport, a' pressure communication tube disposed within said fitting andextending longitudinally of the latter, and means including said casingfor supporting said pressure communication tube in said fitting in afixed relative disposition whereby to provide for the simultaneousconnection of said fitting and said pressure communication tube as aunit to different devices, respectively.

11. A positive pressure device adapted for use with a cyclicallyoperable air pump adapted to alternately produce sub-atmosphericpressure and super-atmospheric pressure, said device comprising a casinghaving a pair of spaced ports which are adapted to be in communicationwith each other cyclically when super-atmospheric pressure is admittedinto one of said ports, and valve means for interconnecting said portswhen super-atmospheric pressure is admitted into one of said ports, saidvalve means being operative to disconnect said ports from communicationwhen sub-atmospheric pressure is applied to said one port, said casinghaving a fitting defining a fluid passage communicating with said oneport, a pressure communication tube disposed Within said fitting andextending longitudinally of the latter through said casing to the otherof said ports, fi'iid fitting having means for supporting said pressurecommunication tube therein whereby to provide for the simultaneousconnection of said fitting and said pressure communication tube as aunit to difierent devices, respectively.

12. In combination with respirator pumping apparatus having pumpingmeans to periodically supply air to and withdraw air from a port and apressure indicating gage associated therewith, a positive pressuredevice adapted for fluid communication with said port, said devicecomprising a casing having a fitting defining a fluid passage, thelatter being adapted for fluid communication with said port, a pressurecommunication tube disposed within said fitting and extendinglongitudinally of the latter, means for supporting said pressurecommunication tube in said fitting in a fixed relative disposition, andmeans providing for the automatic releasable interconnection of saidpressure communication tube with said gage upon efiecting theinterconnection of said positive pressure device fitting with saidpumping means.

13. In combination with respirator pumping apparatus having pumpingmeans to periodically supply air to and withdraw air from a port, aconduit adapted for periodic fluid communication With said port, and apressure indicating gage associated with said pumping means andpositioned remote from said conduit, a positive pressure deviceconnected to said conduit in fluid-flow relation with said port, saiddevice having means for interconnecting said port and said conduit forfluid communication when said pumping means is operative to supply airto said port, said means being efiective to disconnect said port andsaid conduit from fluid communication when said pumping means isoperative to withdraw air from said port, said device having a pressurecommunication tube extending therein, one end of said tube being adaptedfor interconnection with said gage and the opposite end thereofterminating in a free end portion in the region of said conduit wherebysaid gage indicates the pressure in said region, and means providing forthe automatic interconnection of the one end of said tube with said gageon the interconnection of said device with said pumping means.

14. In combination with respirator pumping apparatus having pumpingmeans to periodically supply air to and withdraw air from a port, aconduit adapted for periodic fluid communication with said port, and apressure indicating gage associated with said pumping means andpositioned remote from said conduit, a positive pressure deviceconnected to said conduit in fluid-flow relation with said port, saiddevice having means for interconnecting said port and said conduit forfluid communication when said pumping means is operative to supply airto said port, said means being efiective to disconnect said port andsaid conduit from fluid communicaion when said pumping means isoperative to withdraw air from said port, said device having a pressurecommunication tube extending therein, one end of said tube being adaptedfor interconnection with said gage and the opposite end thereofterminating in a free end portion in the region of said conduit wherebysaid gage indicates the pressure in said region, and means providing forthe automatic interconnection of the one end of said tube with said gageon the interconnection of said device with said pumping means, said lastmentioned means including a coupling member having a pressurecommunication tube portion extending therein, one end of said tubeportion being adapted for interconnection with said gage and the0pposite end of said tube portion being adapted for interconnection withsaid one end of said tube on the inter-- having pumping means toperiodically supply air to and withdraw air from a port, a conduitadapted for periodic fluid communication with said port, and a pressureindicating gage associated with said pumping means and positioned remotefrom said conduit, a positive pressure device connected to said conduitin fluid flow relation with said port, said device having means forinterconnecting said port and said conduit for fluid communication whensaid pumping means is operative to supply air to said port, said meansbeing effective to disconnect said port and said conduit from fluidcommunication when said pumping means is operative to withdraw air fromsaid port, said device having a pressure communication tube extendingtherein, one end of said tube being adapted for interconnection withsaid gage and the opposite end thereof terminating in a free end portionin the region of said conduit whereby said gage indicates the pressurein said region, a coupling member having a pressure communication tubeportion extending therein, opposite ends of said tube portion beingadapted for interconnection with said one end of said tube and saidgage, respectively, on the interconnection of said coupling member withsaid device and said pumping means, and means providing for theautomatic releasable interconnection of said opposite ends of said tubeportion with said one end of said tube and said gage, respectively, onthe interconnection of said coupling member with said device and saidpumping means.

16. In respirator apparatus having pumping means adapted to periodicallysupply air to and withdraw air from a port, a conduit adapted forperiodic fluid communication with said port, a casing for housing saidpumping means having an instrument panel associated therewith, and apressure indicating gage positioned on said panel, a positive pressuredevice connected to said conduit in fluid-flow relation with said port,said device having means for interconnecting said port and said conduitfor fluid communication when said pumping means is operative to supplyair to said port, said means being effective to disconnect said port andsaid conduit from fluid communication when said pumping means isoperative to withdraw air from said port, said device having a pressurecommunication tube extending therein, one end of said tube being adaptedfor interconnection with said gage and the opposite end thereofterminating in a free end portion in the region of said conduit wherebysaid gage indicates the pressure in said region, a coupling memberadapted to interconnect said device and said port in fluid-flowrelation, said casing and said device having fittings formedcomplementary to said coupling member, said casing fitting being influid communication with said port, a tube portion in fluid-flow relation with said gage and terminating in a free end portion in theregion of said casing fitting, a pressure com munication tube portionextending in said coupling member, opposite ends of said tube portionbeing adapted for interconnection with said one end of said tube andsaid free end portion, respectively, on the interconnection of saidcoupling member with said casing and de vice fittings, and meansproviding for the automatic releasable interconnection of said oppositeends of said tube portion with said one end of said tube and said freeend portion, respectively, on the interconnection of said couplingmember with said casing and device fittings.

17. In respirator apparatus provided with a chamber within which the airpressure is rythmically varied and which comprises a pump in fluid-flowcommunication with said chamber for rythmically varying the air pressurein the latter, a coupling device connected between said pump and saidchamber and providing the said fluid communication therebetween, apressure communication tube positioned within said coupling device andextending longitudinally of the latter between the opposite endsthereof, said tube being completely disposed internally of the fluidflow passage between the pump and said chamber, a pressure indicatinggage positioned in the vicinity of said pump, a releasable fittingcompletely disposed internally of said fluid flow passage and connectingsaid pressure tube to said gage internally of the fluid flow passagebetween the pump and said chamber for releasably connecting saidpressure tube to said gage, a tube portion completely disposedinternally of said fluid flow passage and terminating in a free endportion in the region of said chamber, and a releasable fittingcompletely disposed internally of said fluid flow passage and connectingsaid pressure tube to said tube portion internally of the fluid-flowpassage between the pump and said chamber for releasably connecting saidtube portion to said gage so that the pressure in the region of saidfree end portion may be indicated at a point remote therefrom.

18. In respirator apparatus provided with a chamber Within which the airpressure is rythmically varied and which comprises a pump in fluid-flowcommunication with said chamber for rythmically varying the air pressurein the latter, a coupling device connected between said pump and saidchamber and providing the said fluid communication therebetween, apressure communication tube positioned within said coupling device andextending longitudinally of the latter between the opposite endsthereof, said tube being completely disposed internally of thefluid-flow passage between the pump and said chamber, a pressureindicating gage positioned in the vicinity of said pump, a releasablefitting completely disposed internally of said fluid-flow passage andconnecting said pressure tube to said gage internally of the fluid-flowpassage between the pump and said chamber for releasably connecting saidpressure tube to said gage, a tube portion completely disposedinternally of said fluid-flow passage and terminating in a free endportion in the region of said chamber, and a releasable fittingcompletely disposed internally of said fluid-flow passage and connectingsaid pressure tube to said tube portion internally of the fluid-flowpassage between the pump and said chamber for releasably connecting saidtube portion to said gage so that the pressure in the region of saidfree end portion may be indicated at a point remote therefrom, saidcoupling device comprising a length of flexible tubing terminating infittings formed complementary to fittings associated with said pump andsaid chamber.

19. In respirator apparatus provided with a chamber within which the airpressure is rythmically varied and which comprises a pump in fluid-flowcommunication with said chamber for rythmically varying the air pressurein the latter, a coupling device connected between said pump and saidchamber and providing the said fluid communication therebetween, apressure communication tube positioned within said coupling device andextending longitudinally of the latter between the opposite endsthereof, said tube being completely disposed internally of the fluidiiow passage between the pump and said chamber, a pressure indicatinggage positioned in the vicinity of said pump, a releasable fittingcompletely disposed internally of said fluid-flow passage and connectingsaid pressure tube to said gage internally of the fluid-flow passagebetween the pump and said chamber for releasably connecting saidpressure tube to said gage, a tube portion completely disposedinternally. of' said fluid-flow passage and terminating in a free endportion in the region of said chamber, and a releasable fittingcompletely disposed internally of said fluid-flow passage and connectingsaid pressure tube to said tube portion internally of the fluid-flowpassage between the pump and said chamber for releasably connecting saidtube portion to said gage so that the pressure in the region of saidfree end portion may be indicated at a point remote therefrom, said pumpand said chamber having fittings adapted for releasableinterconnectionwith said coupling device, and the latter comprising arigid" 17 body part terminating in fittings formed complementary to saidpump and chamber fittings.

20. In respirator apparatus provided with a chamber within which the airpressure is rythmically varied and which comprises a pump in fluid-flowcommunication with said chamber for rythmically varying the air pressurein the latter, a coupling device connected between said pump and saidchamber and providing the said fluid communication therebetween, apressure communication tube positioned within said coupling device andextending longitudinally of the latter between the opposite endsthereof, said tube being completely disposed internally of thefluid-flow passage between the pump and said chamber, a pressureindicating gage positioned in the vicinity of said pump, a releasablefitting completely disposed internally of said fluid-flow passage andconnecting said pressure tube to said gage internally of the fluid-flowpassage between the pump and said chamber for releasably connecting saidpressure tube to said gage, a tube portion terminating in a free endportion in the region of said chamber, and a releasable fittingconnecting said pressure tube to said tube portion internally of thefluid-flow passage between the pump and said chamber for releasablyconnecting said tube portion to said gage so that the pressure in theregion of said free end portion may be indicated at a point remotetherefrom, and means providing for the automatic releasableinterconnection of said releasable fittings connecting said pressurecommunication tube to said gage and said tube portion on theinterconnection of said coupling device with said pump and chamber,respectively.

21. In combination with an air pump cyclically operable to alternatelyproduce sub-atmospheric pressure and super-atmospheric pressure at aport, and a conduit adapted for periodic fluid communication with saidport, a positive pressure device interposed between said conduit andsaid port in fluid flow relation with the latter, said device comprisingcasing structure provided with valve means comprising spaced valve seatsand a single valve engageable with and disengageable from said valveseats for interconnecting said port and said conduit for fluidcommunication when said pump is operative to produce super-atmosphericpressure at said port and to disconnect said port and said conduit fromfluid communication when said pump is operative to producesub-atmospheric pressure at said port, said casing structure having apassage communicating with the atmosphere, and means providing for fluidcommunication between said conduit and said passage when said pump isoperative to produce sub-atmospheric pressure at said port.

22. A positive pressure device adapted for use with a cyclicallyoperable air pump adapted to alternately produce sub-atmosphericpressure and super-atmospheric pressure, said device comprising a casinghaving a pair of spaced ports which are adapted to be in communicationwith each other cyclically when super-atmospheric pressure is admittedinto one of said ports, first valve means within said casing forinterconnecting said ports when super-atmospheric pressure is admittedinto one of said ports, said valve means being operative to disconnectsaid ports from communication when sub-atmospheric pressure is appliedto said one port, first vent means provided in said casing for fluidcommunication with the other of said ports, said first valve means beingoperative to disconnect said other port from communication with saidfirst vent means when super-atmospheric pressure is admitted into saidone port and to connect said other port for communication with saidfirst vent means when sub-atmospheric pressure is applied to said oneport, second valve means provided in said casing, and second vent meansprovided in said casing for fluid communication with said one port, saidsecond valve means being operative to disconnect said one port fromcommunication with said second vent means when super- 1'8atmospheric'pressure is admitted into said one port and to connect saidone port for communication with said second vent means whensub-atmospheric pressure is applied to said one port. I Y 3 23. Apositive pressure device adapted for use with a cyclically operable airpump adapted to alternately produce sub-atmospheric pressure andsuper-atmospheric pressure, said device comprising a casing having apair of spaced ports which are adapted to be in communication with eachother cyclically when super-atmospheric pressure is admitted into one ofsaid ports, first valve means within said casing for interconnectingsaid ports when super-atmospheric pressure is admitted into one of saidports, said valve means being operative to disconnect said ports fromcommunication when sub-atmospheric pressure is applied to said one port,first vent means provided in said casing for fluid communication withthe other of said ports, said first valve means being operative todisconnect said other port from communication with said first vent meanswhen super-atmospheric pressure is admitted into said one port and toconnect said other port for communication with said first vent meanswhen sub-atmospheric pressure is applied to said one port, second valvemeans provided in said casing, and second vent means provided in saidcasing for fluid communication with said one port, said second valvemeans being operative to disconnect said one port from communicationwith said second vent means when super-atmospheric pressure is admittedinto said one port and to connect said one port for communication withsaid second vent means when sub-atmospheric pressure is applied to saidone port, third valve means provided in said casing, and third ventmeans provided in said casing for fluid communication with said otherport, said third valve means being operative to disconnect said otherport from communication with said third vent means and to connect saidother port for communication with said third vent means when apredetermined super-atmospheric pressure is applied to said other port.

24. A positive pressure device adapted for use with a cyclicallyoperable air pump adapted to alternately produce sub-atmosphericpressure and super-atmospheric pressure, said device comprising a casinghaving a pair of spaced ports which are adapted to be in communicationwith each other cyclically when super-atmospheric pressure is admittedinto one of said ports, first valve means within said casing forinterconnecting said ports when super-atmospheric pressure is admittedinto one of said ports, said valve means being operative to disconnectsaid ports from communication when sub-atmospheric pressure is appliedto said one port, first vent means provided in said casing for fluidcommunication with the other of said ports, said first valve means beingoperative to disconnect said other port from communication with saidfirst vent means when super-atmospheric pressure is admitted into saidone port and to connect said other port for communication with saidfirst vent means when sub-atmospheric pressure is applied to said oneport, second valve means provided in said casing, and second vent meansprovided in said casing for fluid communication with said one port, saidsecond valve means being operative to disconnect said one port fromcommunication with said second vent means when super-atmosphericpressure is admitted into said one port and to connect said one port forcommunication with said second vent means when sub-atmospheric pressureis applied to said one port, third valve means provided in said casing,and third vent means provided insaid casing for fluid communication withsaid other port, said third valve means being operative to disconnectsaid other port from communication with said third vent means and toconnect said other port for communication with said third vent meanswhen a predetermined super-atmospheric pressure is applied to said otherport, said first valve means being means.

References Cited in the file of this patent UNITED STATES PATENTS SweenyFeb. 28, 1871 Desant Feb. 13, 1894 Clark Dec. 26, 1916 McAusland Nov. 3,1925 Kocour Dec. 21, 1937 Sloan May 23, 1939 Anderson Oct. 21, 1941Groeniger -5--- Aug. 11, 1942 Smith Jan. 5, 1943 20 Fox .1 May 22, 1945'Fox Sept. 24, 1946 Rausch 2 Sept. 16, 1947 Emerson Oct. 7, 1947 ParsonsJuly 12, 1949 Siebels June 20, 1950 Wilm Jan. 8, 1952 Colton July 21,1953 Leventhal July 28, 1953 Griswold July 28, 1953 FOREIGN PATENTSFrance Dec. 6, 1933 Great Britain Apr. 25, 1951

